Sign letter construction

ABSTRACT

A sign letter includes spaced parallel side walls having front edges and back edges. Spanning at least the front edge portions is a decorative cover plate customarily of translucent &#39;&#39;&#39;&#39;plastic&#39;&#39;&#39;&#39; sheet material. Adhesively holding the cover plate in position is a spaced pair of substantially J-shaped in section lock strips secured to the front edges of the side walls. Preferably, the lateral margins of the lock strips engaging the subjacent surfaces of the cover plate are enlarged to afford a substantial interfacial area for the adhesive. By making each of the enlarged margins in the form of a serif-shaped projection, the lock strips can be locked in place by protuberances adjacent the front edges of the side walls in a one-way interfering relation with the marginal enlargements on the lock strips.

United States Patent 1191 Skoetsch 1451 Sept. 25, 1973 SIGN LETTER CONSTRUCTION [76] Inventor: Paul B. S. Skoetsch, 1428 N.

Madison, Stockton, Calif. 95203 [22] Filed: June 5,1972

21 Appl. No.: 259,976

[52] us. C1....;1'...' .52/758 D, 40/132 R, 52/759 51 1m. (:1. Fl6b 5/00,G09f13/00 58 Field of Search 287/l89.365, 189.36 D,

287/l89.36 J, 189.36 R, 20.92 J, 189.3 S; 40/142 R, 132 R, 125 R Iirimary ExaminerReinaldo P. Machado Attorney--Robert G. West et al.

[57] ABSTRACT A sign letter includes spaced parallel side walls having front edges and back edges. Spanning at least the front edge portions is a decorative cover plate customarily of translucent plastic sheet material. Adhesively holding the cover plate in position is a spaced pair of substantially J-shaped in section lock strips secured to the front edges of the side walls. Preferably, the lateral margins of the lock strips engaging the subjacent surfaces of the cover plate are enlarged to afford a substantial interfacial area for the adhesive. By making each of the enlarged margins in the form of a serifshaped projection, the lock strips can be locked in place by protuberances adjacent the front edges of the side walls in a one-way interfering relation with the marginal enlargements on the lock strips.

4 Claims, 4 Drawing Figures SIGN LETTER CONSTRUCTION The invention relates to improvements in the fabrication of large individual three dimensional letters of the type having an internal source of illumination and at least one light permeable panel.

The market place as well as the patent literature afford several types of sign letter constructions, as disclosed, for example, in R. W. Minogue, U.S. Pat. No. 3,414,305 dated Dec. 3, 1968 for Plastic-Metal Joint And Method For Producing The Same.

Some of the prior art devices involve the bending of portions of the letter material into seam lock configurations similar to that utilized in the sheet metal or canmaking industry. While durable in nature, the laying out and forming of letters with a seam lock wall construction sometimes requires a considerable amount of skilled workmanship and time.

It is therefore an object of the invention to provide a sign letter construction which simplifies the laying out and forming operation even by relatively unskilled personnel.

It is another object of the invention to provide a sign letter construction which is simple to lay out and does not require heavy cement, yet which is strong, durable and free from light leaks.

It is still another object of the invention to provide a system of making sign letters which is versatile in that it can be used with equal facility and to useful advantage in a wide variety of installations.

It is yet a further object of the invention to provide a sign letter construction which uses an inexpensive extrusion of tough yet easily handled material which, therefore, is economical, not only with respect to initial cost but also in connection with fabrication of the letter itself.

It is another object of the invention to provide a system of producing sign letters in which the letters are attractive in appearance and afford all of the classic colorations of gold, silver, black, white and bronze.

An additional object of the invention is to provide a generally improved sign letter construction.

Other objects, together with the foregoing, are attained in the embodiments described in the following description and shown in the accompanying drawings in which:

FIG. 1 is a perspective view of a sign letter constructed pursuant to one form of the invention;

FIG. 2 is a transverse sectional view, to an enlarged scale, the plane of the section being indicated by the line 2-2 in FIG. 1;

FIG. 3 is a fragmentary perspective view, to a greatly enlarged scale, of a portion of a typical side wall and anchor strip of the FIG. 1-2 form of letter prior to assembly; and,

FIG. 4 is a view comparable to FIG. 3 but with the cover plate, side wall and anchor strip in installed position.

While the sign letter construction of the invention is susceptible of numerous physical embodiments, depending upon the environment and requirements of use, substantial numbers of the herein shown and described embodiments have been made, tested and used, and all have performed in an eminently satisfactory manner.

Although capable of being used in a variety of ways, the construction herein finds especial utility in conjunction with the fabrication of letters, usually of rather large size and singular nature, such as are customarily encountered in the signboard and sign industry.

The sign letter construction of the invention, generally designated by the reference numeral 12, comprises a spaced pair of .side walls 13 fabricated of strip or sheet metal material, such as aluminum (0.019 0.024 inch thick, for example) which is bent to form the desired letter outline.

The metal side walls 13 extend laterally from a front edge 14 to a back edge 15 and are sufficiently long to cover all lateral side surfaces of the letter, as appears most clearly in FIG. 1.

Depending upon the particular requirements of the installation, both the front and the back of the letter can be provided with a decorative cover plate 21. In the form of device shown in FIGS. 1 and 2, however, only the front of the letter carries a cover plate. The back of the letter in FIGS. 1 and 2 is provided with a back plate 22, of conventional aluminum-clad and edgesealed plywood material, for example, suitably affixed to the side walls 13, adjacent the rear edges 15, as by sheet metal screws. Elongated sealing strips 24 of foamed elastomeric material are glued to the inner surface of the side walls 13, as shown, so that when the back plate 22 and the side walls 13 are assembled, stray light leaks are prevented and dust and moisture are kept out. The customary internal illumination source and the sign letter mounting brackets (not shown) are both mounted on the back plate 22.

The decorative cover plate 21 is ordinarily of a rigid colored, transparent or translucent plastic" material, of various types well-known in the art. The cover plate 21 is cut to the desired letter configuration by standard equipment widely used in the sign and signboard field.

In order to secure the cover plate 21 firmly in position, a pair of lock strips 26, or anchor strips, is utilized. The lock strips 26 are attached to the respective front edges 14 of the side walls 13 in mirror symmetry and a description of one will therefore serve equally to describe the other. 7 v

In the form of lock strip 26 shown most clearly in FIGS. 2-4, the lock strip is J-shaped in cross-section with the shorter leg 27, or inner band, of the J surmounted by a serif-shaped enlargement 28, or bead.

The enlargement 28 extends along the entire margin of the inner band 27 of the lock strip 26, and is provided with a planar surface 29 having a relatively extensive area to which an adhesive film 31 can be applied, thereby affording a substantial interfacial area with the adjacent side portions of the cover plate 21 (see FIG. 4). By so bonding the cover plate 21 to the lock strips 26, the previous need of gluing the cover plate to the side walls, or to intermediate adhesively-compatible members, is obviated, and a very durable, light-leakfree construction is attained.

The J-shaped lock strip is preferably of an extruded construction comprising a core 33 of Mylar" covered on both sides with a suitably pigmented film 34 of butyrate, for example.

In the form shown most clearly in FIGS. 2-4, the

elongated, J-shaped lock strip 26 includes not only the enlarged serif-like bead 28 running along the lateral margin of the inner band 27, but also an arcuate, recurved, bight portion 35 and an outer band 36 terminating in a linear margin 37. The outer bands 36 extend rearwardly a short distance along the outer sides of the side walls as appears most clearly in FIG. 2 and are in face to face juxtaposition with the underlying side wall surface.

The serif-like enlargement 28, or bead, extending along the lateral margin of the inner band 27 of the lock strip 26 not only provides a relatively extensive bonding surface for the adhesive film interface 31, but it also includes an elongated ledge 38, or protuberance, or flange, presenting a linear shoulder 39 substantially at right angles to the plane of the adjacent inner band Arranged for interlocking facial engagement with the elongated shoulder 39 is a plurality of aligned offset tab members 41 struck outwardly from the aluminum wall surfaces 13 adjacent the front edges 14 thereof. The tabs 41 resemble a wedge in that they include an inclined planar portion 42 and an abrupt vertical face 43. When the lock strips 26 (with the cover plate mounted thereon) are inserted over the front edges 14 of the side wall and urged toward locked position, the elongated flange 38 first encounters the sloping inclined planes 42 of the aligned tabs 41, the planes serving to wedge, or cam open, the lock strip until the flange clears the highest part of the tab, at which juncture the resiliency of the lock strip material suddenly snaps the flange downwardly so that the shoulder 39 is lodged securely behind the tabs, in face to face engagement with the vertical face portion 43 of the tabs.

Once locked in position, as shown most clearly in FIGS. 2 and 4, the two lock strips 26, together with the cover plate 21 are firmly secured. As can be seen, the construction is such that no light can leak through the labyrinthine path defined by the lock strips, and no heavy cement is required to afford a strong rigid installation. Assembly is quickly and easily effected by snapping the cover plate and the attendant lock strips into place, after which no additional adhesive setting up time is required.

Commercially, the channel-shaped member compris ing the aluminum side wall 13, foam seal 24 and J- shaped lock strip 26 would be provided in coiled form, it being only necessary for the fabricator of the sign letter to unroll from the coil whatever length of channel is necessary for the total length of the sign perimeter. This length of channel is thereupon affixed to the plywood back plate 22 (previously cut, as with a band saw,

to the appropriate letter configuration), the back plate 22 also serving as a mounting base for the lamp (not shown) inside the sign, and to hold the brackets by which the sign letter is secured to an adjacent mounting wall or frame.

The decorative cover plate 21, also in the shape of the letter, is affixed to the surface 29 of the lock strip by adhesive 31 and since both the cover plate 21 and the lock strip 26 is of plastic material an especially strong and durable bonding results, the coefficients of expansion being substantially the same.

It can therefore be seen that the resultant letter is not only quickly, easily and economically fabricated, but it also is tough, durable, and free of light leaks.

What is claimed is:

1. A sign letter construction comprising:

a. a spaced pair of side walls having front edges and back edges;

b. a back plate spanning said side walls adjacent said back edges;

c. a pair of elongated substantially J-shaped in section lock strips, each including an inner band, a recurved bight and an outer band;

d. a cover plate capable of spanning said side walls adjacent said front edges, said cover plate being secured to the lateral margin of each of said inner bands of said lock strips; and,

e. means for securing said pair of lock strips to said front edges of said side walls.

2. A sign letter construction as in claim 1 in which each of said lateral margins of said inner bands of said lock strips includes a laterally enlarged portion.

3. A sign letter construction as in claim 2 in which said front edges of said side walls include protuberances arranged for interfering relation with said laterally enlarged portions of said lock strips, said protuberances being shaped so as to allow movement of said lock strips in a first locking direction and to prevent movement thereof in a second reverse direction.

4. A sign letter construction as in claim 3 in which said enlarged portions of said inner band margins include planar surfaces capable of receiving an adhesive film engageable with the adjacent sides of said cover plates. 

1. A sign letter construction comprising: a. a spaced pair of side walls having front edges and back edges; b. a back plate spanning said side walls adjacent said back edges; c. a pair of elongated substantially J-shaped in section lock strips, each including an inner band, a recurved bight and an outer band; d. a cover plate capable of spanning said side walls adjacent said front edges, said cover plate being secured to the lateral margin of each of said inner bands of said lock strips; and, e. means for securing said pair of lock strips to said front edges of said side walls.
 2. A sign letter construction as in claim 1 in which each of said lateral margins of said inner bands of Said lock strips includes a laterally enlarged portion.
 3. A sign letter construction as in claim 2 in which said front edges of said side walls include protuberances arranged for interfering relation with said laterally enlarged portions of said lock strips, said protuberances being shaped so as to allow movement of said lock strips in a first locking direction and to prevent movement thereof in a second reverse direction.
 4. A sign letter construction as in claim 3 in which said enlarged portions of said inner band margins include planar surfaces capable of receiving an adhesive film engageable with the adjacent sides of said cover plates. 